Left alone in the mansion on the holidays, relative X-Men newcomer Kitty Pryde is feeling a bit down. Things get a whole lot worse, however, when a N'garai demon invades the mansion. Kitty, whose only power is the ability to become intangible, must battle this frightening alien alone. At this time in X-History, Kitty has little confidence in herself or her place with the X-Men. She wouldn't consider herself ready for a life or death fight like this. Yet, in the end, it's Kitty's resourcefulness that wins the day.

Great characters have defining moments and this is Kitty's. This is the moment where Kitty truly became an X-Man and also where she won over a majority of her fans. To Marvel's credit, they've never tried to develop Kitty by adding to her powers. She's remained a relatively low-level mutant. But acts like this are what make her one of the greatest X-Men of all time.

Wolverine's origins were partly revealed in Barry Windsor-Smith's "Weapon X" storyline. We learned the grizzly details of Wolverine's time at Weapon X, including when he earned his adamantium skeleton. There were many surprising moments in this story arc, but the one that stands out is the moment that the scientists realize Wolverine is no longer in their control.

After another series of tests, Logan is placed back in his room, supposedly docile. But as his handlers turn, his eyes open, his claws pop out and he murders with jailers. No one is safe. From this moment, Wolverine is his own man, though he acts as little more than animal, tearing his way towards freedom. Ironic that he would spend the next few decades trying to retrace his way back to those origins.

Storm Takes Control of the Morlocks

Uncanny X-Men #170Words: Chris Claremont | Pencils: Paul Smith

The Morlocks had captured the X-Men. Callisto, leader of the underground mutant camp, intended to marry Angel. Kitty Pryde was slowly dying, inflicted by a disease caused by one of the Morlock members. When an attempt to escape failed, the only recourse for the team was to attempt a coup of the Morlock leadership. Storm overrides Nightcrawler's initial bid to challenge Callisto in a hand-to-hand duel to the death. Storm, still sick from the same disease killing Kitty, is clearly not the better fighter. Even worse, Ororo Monroe previously said she would never take another person's life. After being cut several times, Storm ensnared Callisto with her cape, and stabbed her enemy in the chest. Having won the fight, and control of the Morlocks, Storm freed her teammates.

Prior to this brutal fight, Storm had never been portrayed in this manner. It solidified her status as the leader of the X-Men in Cyclops' absence, and showed her to be a formidable fighter without her powers. The X-Men, both the team and the series, needed a strong secondary field commander. After her fight with Callisto, there was no question Storm was a perfect fit. The fight also showed Storm's strength as a person. She had vowed to never take a life, but was willing to cross that line to save Kitty and the lives of the other X-Men. Storm was willing to stand against seemingly unbeatable odds for her teammates.

A metaphor for race relations, God Loves, Man Kills is considered one of Chris Claremont's best X-Men stories. Reverend William Stryker is a zealot who believes mutants are evil. When his son was born with an obvious mutation, Stryker went nuts. He murdered his newborn son and killed his wife for spawning such a creature. He goes so far as to kidnap Professor X in an insane plan to kill every mutant on Earth. He is stopped, not by the X-Men or Magneto's Brotherhood, but by his own security guard.

After attempting to kill Kitty Pryde, the security guard finally realizes that mutants are not a threat simply for being mutants. He shoots Stryker, putting an end to the madness. So often it is up to the X-Men to prove that man and mutant can live in peace. In this rare instance, we see that humans can still overcome their own bigotry and accept the differences in others.

Wolverine Faces Hellfire

Uncanny X-Men #133Words: Chris Claremont | Pencils: John Byrne

We all know that Wolverine's the best at what he does, but before this issue, no one knew Logan could be a true badass. Coming before the miniseries that would truly define his character, Wolverine's assault on the Hellfire Club gave notice that this was one Canadian you did not want to f--- with. At the end of UXM #132, the X-Men have been thoroughly thrashed, with Wolverine presumed dead. As we see in the final panel of the issue, Logan's alive and ready for payback.

The X-Men's lone hope, Wolverine tears through the HFC's guards, determined to put a claw on those responsible for turning Jean against the X-Men. Though, ultimately, he is swarmed and defeated at the end of the issue, Wolverine gave notice that he was going to be a major player in the X-Universe from then on.